What to Watch When Running Fermented Dough on a Machine

Steamed buns, mantou, xiaolongbao, and silver thread rolls all use fermented dough. Compared with dumpling dough, fermented dough is "alive"; it keeps changing in the hopper and on the conveyor. Whether machine production goes smoothly depends largely on getting the timing of fermentation right.

Wrap First and Then Ferment, or Ferment First and Then Wrap?

In machine production of steamed buns and mantou, the common process is mixing, a short rest, encrusting and forming on the machine, panning for final proofing, and steaming. In other words, the main fermentation happens after forming, so the dough has little gas and a tight structure when it goes on the machine, which makes encrusting and sealing more stable and every piece the same weight.

Some products let the dough go through a period of bulk fermentation before going on the machine, for better flavor and crumb, but then the dough is already aerated when it goes on the machine, and the air bubbles get squeezed during feeding and cutting, making weight and shape harder to control. Which approach suits you depends on the desired texture and the pace of the line.

Can Overfermented Dough Still Run on the Machine?

It is not recommended. Overfermented dough has several problems:

• Weakened gluten: The gluten has been stretched too far by gas, to the limit of its extensibility, so it tears as soon as it is stretched during encrusting.
• Large, uneven air bubbles: After forming, the surface is pitted, and the buns tend to collapse after steaming.
• Sour taste: Fermenting too long makes the flavor sour.
• Unstable weight: The amount of air in the same volume varies, so divided weights drift.

If the dough is already overfermented, a more practical approach is to knead and degas it again, let it rest briefly, and then use it, or downgrade it to another product, rather than forcing it onto the machine.

How to Manage Fermentation on the Machine

1. Control dough temperature: The warmer it is, the more active the yeast. In summer, mix with cold water so the dough is on the cool side when it goes on the machine; see Dough Temperature and Resting Time.
2. Load small amounts frequently: Do not put too much in the hopper at once, so the dough at the back end has not already risen.
3. Fix the time from mixing to the machine: Keep conditions consistent from start to finish for the same batch, so sizes stay consistent.
4. Control temperature and humidity during final proofing after forming: Proofer conditions determine whether the buns stand tall after steaming; for why buns collapse after steaming, see Unclear Bun Pleats and Collapse After Steaming.

How to Handle Frozen Dough

Before frozen dough goes on the machine, the most important thing is uniform tempering. If the outer layer has thawed while the center is still hard, its firmness will be uneven on the machine, causing torn wrappers and uneven thickness. The method is to move it to the refrigerator in advance to thaw slowly, then bring it to the work area to reach a workable temperature; keep the surface covered so it does not become sticky from condensation or dry out and form a skin. Yeast activity may decline in frozen dough, so adjust final proofing time based on actual observation.

RHEON's model list also includes optional mechanisms dedicated to the pleats of Chinese-style steamed buns, which shows that mechanizing bun-type products has always been a specialized field of its own.

Dong-Yih Machinery's DY-201 Automatic Steamed Bun and Mantou Machine is designed around a traditional technique that does not break down the dough structure, with an output of 2,000–12,000 pieces/hour. To do a test run with your own dough, please call 06-257-4644.

FAQ

Q: Are steamed buns wrapped first and then fermented, or fermented first and then wrapped?
A: In machine production, wrapping first and fermenting afterward is common; the dough has little gas and a tight structure when it goes on the machine, so forming and weight are more stable.

Q: Can overfermented dough still run on the machine?
A: It is not recommended; the weakened gluten tends to tear and slump, and the weight is unstable. You can knead and degas it again before using it.

Q: Can frozen dough go straight on the machine?
A: It should first be thawed slowly in the refrigerator, then brought to a workable temperature, with its firmness uniform inside and out, before going on the machine.

Q: Why are my buns getting bigger and bigger?
A: Most likely the dough is continuing to ferment in the hopper. Lower the dough temperature and load small amounts frequently.